Properties of the Number 20155

Twenty Thousand One Hundred Fifty-Five

Basics

Value: 20154 → 20155 → 20156

Parity: odd

Prime: No

Previous Prime: 20149

Next Prime: 20161

Digit Sum: 13

Digital Root: 4

Palindrome: No

Factorization: 5 × 29 × 139

Divisors: 1, 5, 29, 139, 145, 695, 4031, 20155

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

Today's Target

2196 Try Today's Challenge

Representations

Binary: 100111010111011

Octal: 47273

Duodecimal: B7B7

Hexadecimal: 4ebb

Square: 406224025

Square Root: 141.96830632222108

Classification

Fibonacci: No

Bell Number: No

Factorial Number: No

Regular Number: No

Perfect Number: No

Special

Kaprekar Constant: No

Munchausen Constant: No

Armstrong Number: No

Kaprekar Number: No

Catalan Number: No

Vampire Number: No

Taxicab Number: No

Super Prime: No

Friedman Number: No

Fermat Number: No

Cullen Number: No

OEIS Sequences

Numbers k such that k and k+1 have the same sum of unitary divisors (A034448). A64125

Numbers k such that bsigma(k) = bsigma(k+1), where bsigma(k) is the sum of the bi-unitary divisors of k (A188999). A293183

Numbers k such that isigma(k) = isigma(k+1), where isigma(k) is the sum of the infinitary divisors of k (A049417). A306985

Column 10 of array illustrated in A089574 and related to A034261. A108538

Numbers n such that σ(n-1) + σ(n+1) = σ(2n). A67730

Numbers k such that iphi(k) = iphi(k+1), where iphi is the infinitary totient function (A064380). A301866

Numbers k such that A113184(k) = A113184(k+1). A348585

Solve 2ⁿ - 2 = 7(x² - x) + (y² - y) for (x,y) with x>0, y>0; a(n) = value of y. A76631

Column 11 of table A105552. A110554

a(n) = numerator of constant λ(n) involved in a recurrence for the Atkin polynomials A_k(j). A145226